Display devices with adjustable viewing angle functions can provide different viewing angles to meet the viewing needs of different users. For example, a display device with adjustable viewing angle may provide two viewing modes, i.e., a private viewing mode and a normal viewing mode. In a private viewing mode, the viewing angle of the display device is sufficiently narrow to prevent people nearby from viewing the content displayed on the display device. In a normal viewing mode, the viewing angle of the display device is sufficiently wide to allow people to view the content displayed on the display device from a sufficiently large viewing angle.
A display device with adjustable viewing angle functions often includes a backlight module, a switchable diffuser, and a display panel. Problems arise, however, as the size of display devices increases, the area of the switchable diffuser keeps increasing accordingly. As a result, the fabrication cost of the display device can be undesirably increased.